
I had this exact same problem with my lurcher pup, he is now 7 months, and comes up and down without a problem.
However, he used to just go up, and then stand at the top and cry for me to come and get him!
I started off gently helping him down, encouraging him with food, and it took about a week or two for him to learn how to do it on his own.
He does have a very different method from my other dogs. Dilly comes down by bouncing, front legs together, then back legs together. Saffi doesnt like stairs much, so aviods them at all costs. Rocky comes down at an angle, just normal foot steps though!
I guess Dill is just odd! well, he is a lurcher, so he is allowed. I wish he hadnt learned how to get up stairs though, he always causes trouble up there!
Em